Mask holder for irradiating UV-rays

ABSTRACT

A mask holder for irradiating UV-rays is disclosed in the present invention. The mask holder includes a lower part having a frame and a mask supporting member supporting a mask, wherein the mask supporting member is in the frame and has a plurality of first connecting portions, and an upper part having a plurality of second connecting portions to be aligned with the first connecting portions.

This application is a Continuation of prior application Ser. No.10/245,498, filed Sep. 18, 2002 now U.S. Pat. No. 7,006,202.

This application claims the benefit of the Korean Application Nos.P2002-009338 filed on Feb. 21, 2002, P2002-009612 filed on Feb. 22,2002, and P2002-009613 filed on Feb. 22, 2002, which are herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus for fabricating a liquidcrystal display device, and more particularly, to a mask holder forirradiating UV-rays.

2. Discussion of the Related Art

A thin flat panel display tends to have a thickness of no more than afew centimeters and is operated at a low voltage. Such displays consumeless power and are portable. Among them, a liquid crystal display devicehas been the most widely used in various fields such as a notebookcomputer, a computer monitor, a gauge monitor for spacecrafts andairplanes, and the like.

Such a liquid crystal display device, as shown in FIG. 1, generallyincludes a lower substrate 1 having a plurality of thin film transistors(not shown) and pixel electrodes 3 formed thereon, an upper substrate 2having a black matrix layer 4, a color filter layer 6, and a commonelectrode 8, and a liquid crystal layer 5 between the lower and uppersubstrates 1 and 2. Electric fields are generated between the pixel andcommon electrodes 3 and 8 so as to drive the liquid crystal layer 5.Light transmittance is controlled through the driven liquid crystallayer 5 in order to display images on the display screen.

Moreover, alignment layers (not shown) are formed on the front sides ofthe substrates 1 and 2 for an initial alignment of the liquid crystals5.

A sealant 10 is formed between the lower and upper substrates 1 and 2 soas to prevent liquid crystals from leaking out of the substrates and tobond the substrates to each other.

The sealant 10 is coated on the lower or upper substrate 1 or 2, and isthen hardened after attaching the lower and upper substrates 1 and 2 toeach other. Types of such sealants include a thermo-hardening sealantand a UV-hardening sealant, which are hardened by heat and UV-rays,respectively.

Meanwhile, the type of sealant may be selected from one of thethermo-hardening sealant and the UV-hardening sealant depending on themethod of fabricating a liquid crystal display device.

In a vacuum injection method for injecting liquid crystals in theattached substrates using a capillary phenomenon and a pressuredifference, the sealant is hardened before the liquid crystals areinjected after attaching the lower and upper substrates to each other.There is no chance of contaminating the liquid crystals even if thesealant leaks out. Hence, the vacuum injection method mainly uses thethermo-hardening sealant.

In the liquid crystal dropping method, the attaching process of twosubstrates is carried out after dispensing the liquid crystals on one ofthe substrates 1 and 2. The sealant is hardened after forming the liquidcrystal layer. Hence, when the thermo-hardening sealant is used, thesealant flows out during a heating process, thereby contaminating theliquid crystals. Therefore, the UV hardening sealant is mainly used foran LCD formed by the liquid crystal dropping method.

FIG. 2 is a perspective view illustrating a UV emitting device forhardening a UV-hardening sealant in a liquid crystal display deviceusing the liquid crystal dropping method of the related art.

Referring to FIG. 2, a UV emitting device of the related art includes asubstrate stage 20 and a UV source unit 30 having a UV lamp 32 placedover the substrate stage 20.

A hardening process of a sealant using such a UV emitting device of therelated art is carried out in a manner that UV-rays are irradiated bythe UV source unit 30 to attached substrates 1 and 2 loaded on thesubstrate stage 20 of the UV emitting device. In this case, aUV-hardening sealant 10 is formed inside the attached substrates 1 and2.

In the UV emitting device of the related art, the UV-rays from the UVsource unit 30 are irradiated to the entire surface of the substratestage 20 on which the attached substrates are loaded. Thus, the UV-raysare irradiated onto the entire exposed surface of the attachedsubstrates.

However, once the UV-rays are irradiated to the entire surface of theattached substrates, characteristics of devices on the substrate, suchas thin film transistors and the like, are degraded. Moreover, apre-tilt angle of the alignment layer for an initial alignment of theliquid crystals is changed.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a mask holder forirradiating UV-rays that substantially obviates one or more of problemsdue to limitations and disadvantages of the related art.

Another object of the present invention is to provide a mask holder forirradiating UV-rays, which includes a mask for selectively irradiatingUV-rays only on a sealant-formed area, so as to harden a UV-hardeningsealant without degrading characteristics of devices on the substrates,such as alignment layers, thin film transistors, and the like.

Another object of the present invention is to provide a mask holder forirradiating UV-rays effectively securing a mask.

Additional features and advantages of the invention will be set forth inthe description which follows and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, a maskholder for irradiating UV-rays includes a lower part having a frame anda mask supporting member supporting a mask, wherein the mask supportingmember is in the frame and has a plurality of first connecting portions,and an upper part having a plurality of second connecting portions to bealigned with the first connecting portions.

In another aspect of the present invention, a UV emitting deviceincludes a substrate stage, a UV source unit, a mask between thesubstrate stage and the UV source unit, and a mask holder including alower part having a frame and a mask supporting member supporting amask, wherein the mask supporting member is in the frame and has aplurality of first connecting portions, and an upper part having aplurality of second connecting portions to be aligned with the firstconnecting portions.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiments of the invention andtogether with the description serve to explain the principle of theinvention.

In the drawings:

FIG. 1 illustrates a schematic cross-sectional view of a related artliquid crystal display device;

FIG. 2 is a schematic perspective view illustrating a UV emitting devicefor hardening a UV-hardening sealant in a liquid crystal display deviceusing a related art liquid crystal dropping method;

FIG. 3 is an expanded perspective view illustrating a UV emitting deviceaccording to the present invention;

FIG. 4A is an expanded perspective view illustrating a mask holderaccording to a first embodiment of the present invention;

FIG. 4B illustrates a layout of a mask secured by the mask holder ofFIG. 4A;

FIG. 4C illustrates a cross-sectional view taken along line IVC-IVC ofFIG. 4B;

FIGS. 5 to 7 illustrate mask holders for a UV emitting device accordingto second, third, and fourth embodiments of the present invention,respectively;

FIG. 8A is an expanded perspective view illustrating a mask holderaccording to a fifth embodiment of the present invention;

FIG. 8B illustrates a layout of a mask secured by the mask holder ofFIG. 8A;

FIG. 8C illustrates a cross-sectional view taken along line VIIIC-VIIICof FIG. 8B;

FIG. 9 is an expanded perspective view illustrating a mask holder for aUV emitting device according to a sixth embodiment of the presentinvention;

FIG. 10A is an expanded perspective view illustrating a mask holderaccording to a seventh embodiment of the present invention;

FIG. 10B illustrates a layout of a mask secured by the mask holder ofFIG. 10A;

FIG. 10C illustrates a cross-sectional view taken along line XC-XC ofFIG. 10B;

FIGS. 11 to 13 illustrate mask holders for a UV emitting deviceaccording to eighth, ninth, and tenth embodiments of the presentinvention, respectively;

FIG. 14A is an expanded perspective view illustrating a mask holderaccording to an eleventh embodiment of the present invention;

FIG. 14B illustrates a layout of a mask secured by the mask holder ofFIG. 14A;

FIG. 14C illustrates a cross-sectional view taken along line XIVC-XIVCof FIG. 14B;

FIG. 14D illustrates a cross-sectional view taken along line XIVD-XIVDof FIG. 14B;

FIGS. 15A and 15B are expanded perspective views illustrating maskholders according to a twelfth embodiment of the present invention; and

FIGS. 16 to 20 illustrate mask holders according to thirteenth,fourteenth, fifteenth, sixteenth, and seventeenth embodiments of thepresent invention, respectively.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Reference will now be made in detail to the illustrated embodiments ofthe present invention, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.

FIG. 3 is an expanded perspective view illustrating a UV emitting deviceaccording to the present invention.

Referring to FIG. 3, a UV emitting device according to the presentinvention includes a substrate stage 100, a UV source unit 200, a mask300 formed between the substrate stage 100 and the UV source unit 200,and lower and upper parts 400 and 500 securing the mask 300.

Attached substrates 700 in which a sealant 750 is formed thereon areloaded on the substrate stage 100. The substrate stage 100 may be movedby using a conveyer belt, or the like, for mass production.

A UV lamp 210 is formed in the UV source unit 200. Although only one UVlamp is illustrated in the drawing, a plurality of UV lamps may beinstalled as a substrate size increases.

The mask 300 has the same pattern 310 as that of the sealant 750 so thatUV-rays are irradiated to the area of the attached substrate 700 wherethe sealant 750 is formed. Therefore, the mask pattern 310 may bechanged depending on variation of the pattern of the sealant 750 withdifferent models.

The mask 300 is placed and secured between the lower and upper parts 400and 500. Shapes of the lower and upper parts 400 and 500 and a method ofsecuring the mask 300 to the mask holders are explained as follows.

FIG. 4A is an expanded perspective view illustrating a mask holderaccording to a first embodiment of the present invention. FIG. 4Billustrates a layout of a mask secured by the mask holder of FIG. 4A.FIG. 4C illustrates a cross-sectional view taken along line IVC-IVC ofFIG. 4B.

Referring to FIG. 4A, a mask holder according to a first embodiment ofthe present invention includes a lower part 400, an upper part 510, andconnecting members 600 connecting the upper part 510 and the lower part400.

In this case, the lower part 400 includes a rectangular frame 410 andplate members 440. First connecting portions 450 are formed at each ofthe plate members 440.

The plate members 440 support the mask 300 and are formed at the rightand left sides of the rectangular frame 410. The plate members 440 mayalso be formed at the upper and lower sides of the rectangular frame410.

The upper part 510 includes a pair of straight bars. Second connectingportions 550 are formed at the upper part 510 and correspond to thefirst connecting portions 450 of the plate members 440.

The upper part 510 is fastened to the plate members 440 formed insidethe rectangular frame 410 and has a size matching the plate members 440.

A method of securing a mask to the above-explained mask holder, as shownin FIGS. 4B and 4C, includes aligning the mask 300 with the platemembers 440 of the lower part 400, placing the upper part 510 over themask 300, and putting the connecting member 600 into the first andsecond connecting portions 450 and 550 of the plate members 440 andupper part 510, respectively, to secure the mask 300.

Meanwhile, as mentioned in the foregoing explanation, since a pattern ofthe mask 300 may be changed according to a product model, the mask 300may also be replaced. Hence, the connecting member 600 does notpermanently secure the upper part 510 to the lower part 400 but isdetachable like bolts and the like.

Moreover, UV-rays pass through the pattern 310 of the mask 300 so as tobe irradiated onto the sealant of the attached substrate. If a portionof the pattern 310 of the mask 300 overlaps the plate members 440, theUV-rays cannot be irradiated to the sealant of the attached substrate.Therefore, the plate members 440 of the lower part 400 securing the mask300 and the upper part 510 may be formed of a UV transparent material,such as acryl, quartz, and the like.

FIGS. 5 to 7 illustrate mask holders for a UV emitting device accordingto second, third, and fourth embodiments of the present invention,respectively, in which a mask is placed and secured between the lowerand upper parts, as shown in the first embodiment.

A mask holder according to a second embodiment of the present inventionin FIG. 5 is similar to that of the first embodiment in FIG. 4A, exceptfor the shape of the upper part. Therefore, the same numerals are usedin FIG. 5, and explanations will be omitted for simplicity.

The mask holder according to a second embodiment of the presentinvention, as shown in FIG. 5, includes a rectangular member 520 as anupper part instead of a pair of the straight bars. The rectangularmember 520 secures the mask with better stability.

A mask holder according to a third embodiment of the present invention,as shown in FIG. 6, includes a plate member 440 formed at all four sidesinside the lower part 400. The other parts of the third embodiment arethe same as those of the mask holder of the first embodiment shown inFIG. 4A.

A mask holder according to a fourth embodiment of the present invention,as shown in FIG. 7, includes a plate member 440 formed at all four sidesinside the lower part 400 and a rectangular member 520 as an upper part.

Thus, a contact area between the mask and the mask holder supporting themask is increased, thereby securing the mask with better stability.

FIG. 8A is an expanded perspective view illustrating a mask holderaccording to a fifth embodiment of the present invention. FIG. 8Billustrates a layout of a mask secured by the mask holder of FIG. 8A.FIG. 8C illustrates a cross-sectional view taken along line VIIIC-VIIICof FIG. 8B.

A mask holder according to a fifth embodiment of the present invention,as shown in FIGS. 8A to 8C, includes a plate 430 located at the bottominside a rectangular frame 410 of a lower part 400 and supporting theentire side of the mask. Therefore, a contact area between the mask andthe mask holder is maximized, thereby securing the mask with betterstability.

In this case, the plate 430 is formed of a UV transparent material, suchas acryl or quartz, so that the UV-rays are irradiated to the patternformed in the mask. The other parts are similar to those of the maskholder shown in FIG. 4A, and the same numerals are used for the sameparts.

FIG. 9 is an expanded perspective view illustrating a mask holder for aUV emitting device according to a sixth embodiment of the presentinvention. The mask holder is similar to that of the first embodimentshown in FIG. 4A except for the upper part. In this embodiment, arectangular member 520 is used for the upper part.

FIG. 10A is a perspective view illustrating a mask holder according to aseventh embodiment of the present invention. FIG. 10B illustrates alayout of a mask secured by the mask holder of FIG. 10A. FIG. 10Cillustrates a cross-sectional view taken along line XC-XC of FIG. 10B.

Referring to FIG. 10A, a mask holder according to a seventh embodimentof the present invention includes a lower part 400, an upper part 510,and a connecting member 600 connecting the upper part 510 into the lowerpart 400.

In this case, the lower part 400 includes a rectangular frame 410 and aplurality of protrusion members 420 formed inside the rectangular frame410. First connecting portions 450 are formed at each of the protrusionmembers 420 at the corners of the rectangular frame 410.

The protrusion members 420 support the mask. A plurality of theprotrusion members 420 are formed on the right and left sides of therectangular frame 410. The protrusion members 420 may also be formed atthe upper and lower sides of the rectangular frame 410.

The upper part 510 includes a pair of straight bars. Second connectingportions 550 are formed at the upper part 510 and correspond to thefirst connecting portions 450 of the protrusion members 420.

The upper part 510 is fastened to the protrusion members 420 formedinside the rectangular frame 410 and having a size matching therectangular frame 410.

Meanwhile, as mentioned in the foregoing explanation, since a pattern ofthe mask 300 may be changed with a different product model, the mask 300may also be replaced. Hence, the connecting member 600 does notpermanently secure the upper part 510 to the lower part 400 but may bedetachable like bolts and the like.

Moreover, the UV-rays pass through the pattern 310 of the mask 300 so asto be irradiated to the sealant of the attached substrate. If a portionof the pattern 310 of the mask 300 overlaps the protrusion members 420,the UV-rays cannot be irradiated to the sealant of the attachedsubstrate. Therefore, the protrusion members 420 of the lower part 400securing the mask 300 and the upper part 510 are formed of a UVtransparent material, such as acryl, quartz, and the like.

FIGS. 11 to 13 illustrate mask holders for a UV emitting deviceaccording to eighth, ninth, and tenth embodiments of the presentinvention, respectively.

A mask holder according to the eighth embodiment of the presentinvention, as shown in FIG. 11, includes a rectangular frame 520 as anupper part instead of a pair of the straight bars. The other parts aresimilar to those of the mask holder according to the seventh embodimentof the present invention.

A mask holder according to the ninth embodiment of the presentinvention, as shown in FIG. 12, includes a plurality of protrusionmembers 420 formed at all four sides inside the lower part 400 insteadof the left and right sides or the upper and lower sides of the lowerpart 400. The other parts are the same as those of the mask holderaccording to the seventh embodiment of the present invention.

A mask holder according to the tenth embodiment of the presentinvention, as shown in FIG. 13, includes a plurality of protrusionmembers 420 formed at all four sides inside the lower part 400 and arectangular frame 520 as an upper part.

If more pieces of the protrusion members 420 in the lower part 400 isused or the rectangular frame 520 is used as the upper part, the maskmay be supported more stably. However, a contact area between the maskand the mask holder is increased, so that the UV-rays may not beirradiated to the mask pattern depending on the sealant pattern. Hence,the sealant may not be hardened.

Therefore, the protrusion members 420 and the rectangular frame 520 maybe formed of a UV transparent material, such as acryl, quartz, and thelike.

FIG. 14A is an expanded perspective view illustrating a mask holderaccording to an eleventh embodiment of the present invention. FIG. 14Billustrates a layout of a mask secured by the mask holder of FIG. 14A.FIG. 14C illustrates a cross-sectional view taken along line XIVC-XIVCof FIG. 14B. FIG. 14D illustrates a cross-sectional view taken alongline XIVD-XIVD of FIG. 14B.

Referring to FIG. 14A, a mask holder according to an eleventh embodimentof the present invention includes a lower part 400, an upper part 510,and a connecting member 600 connecting the upper part 510 into the lowerpart 400.

In this case, the lower part 400 includes a rectangular frame 410, aplurality of protrusion members 420 formed inside the rectangular frame410, and a supporting bar 460 attached to two of the protrusion members420. First connecting portions 450 are formed at each of the protrusionmembers 420 at the corners of the rectangular frame 410.

The protrusion members 420 are the main support for the mask, and thesupporting bar 460 is a secondary mask support. More specifically, whena size of the substrate increases, the mask also increases accordingly.Hence, the central portion of the mask may be bent down if the mask issupported only by the protrusion members 420. Therefore, the supportingbar 460 prevents such a problem.

In this case, a portion of the pattern 310 of the mask 300 through whichthe UV-rays are irradiated to the sealant in the attached substrateoverlaps the supporting bar 460 as the secondary mask support. Hence,the supporting bar 460 is formed of a UV transparent material, such asacryl, quartz, and the like.

As shown in the drawing, protrusion members 420 and the supporting bar460 are formed at the right and left sides of the rectangular frame 410,respectively. The protrusion members 420 and the supporting bar 460 mayalso be formed at the upper and lower sides of the rectangular frame410, respectively. Moreover, widths of the protrusion members 420 andthe supporting bar 460 may be varied with other conditions. Also, morethan one supporting bars 460 may be installed in the lower part 400.

The upper part 510 includes a pair of straight bars. Second connectingportions 550 are formed at the upper part 510 and correspond to thefirst connecting portions 450 of the protrusion members 420.

The upper part 510 is fastened into the protrusion members 420 formedinside the rectangular frame 410 so as to have a size matching therectangular frame 410.

Meanwhile, as mentioned in the foregoing explanation, since a pattern ofthe mask 300 may be changed according to a product model, the mask 300may also be replaced. Hence, the connecting member 600 does notpermanently secure the upper part 510 to the lower part 400 and may bedetachable like bolts and the like.

Moreover, the UV-rays pass through the pattern 310 of the mask 300 so asto be irradiated to the sealant of the attached substrate. If a portionof the pattern 310 of the mask 300 overlaps the protrusion members 420,the UV-rays cannot be irradiated to the sealant of the attachedsubstrate. Therefore, the protrusion members 420 of the lower part 400holding the mask 300 and the upper part 510 are formed of a UVtransparent material, such as acryl, quartz, and the like.

FIGS. 15A and 15B are expanded perspective views illustrating maskholders according to a twelfth embodiment of the present invention, inwhich a supporting bar 460 is connected to inner sides of a rectangularframe 410 where the protrusion members 420 are not attached and theother parts are similar to those of the eleventh embodiment of thepresent invention. Hence, the same numerals are used to the other parts.

Referring to FIG. 15A, the supporting bar 460 is connected to innersides of the rectangular frame 410 without forming the protrusionmembers 420 thereon. Referring to FIG. 15B, the supporting bar 460 isconnected to inner faces of the rectangular frame 410 between aplurality of the protrusion members 420.

FIGS. 16 to 20 illustrate mask holders according to thirteenth,fourteenth, fifteenth, sixteenth, and seventeenth embodiments of thepresent invention, respectively.

Referring to FIGS. 16 to 20, mask holders according to the thirteenth toseventeenth embodiments of the present invention are variouscombinations of the above-described embodiments of the presentinvention.

Accordingly, the present invention is to irradiate UV-rays only on asealant-formed area to harden a UV-hardening sealant without degradingcharacteristics of devices on the substrates, such as the alignmentlayers, the thin film transistors, and the like.

Moreover, the mask holder according to the present invention effectivelysecures the mask, and may be varied with the mask patterns regardless ofchanges in the sealant pattern.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the mask holder forirradiating UV-rays of the present invention without departing from thespirit or scope of the inventions. Thus, it is intended that the presentinvention covers the modifications and variations of this inventionprovided they come within the scope of the appended claims and theirequivalents.

1. A method of manufacturing a liquid crystal display (LCD) devicecomprising: preparing a first substrate and a second substrate; forminga sealant on one of the first and second substrates; applying liquidcrystal on one of the first and second substrates; and attaching thefirst and second substrates; curing the sealant by irradiating UV lightthrough a mask, wherein the mask is supported by a mask holder, whereinthe mask holder includes: a lower part having a frame and a masksupporting member supporting a mask under the mask, wherein the masksupporting member directly contacts with a lower surface of the mask inthe frame and has a plurality of first connecting holes formed in themask supporting member; and an upper part having a pair of firststraight bars and a plurality of second connecting holes, formed in thepair of the first straight bars, to be aligned with the first connectingholes; and a plurality of connecting members coupled with the pluralityof first and second connecting holes, so that the first straight barsare coupled with the mask supporting member; wherein the frame of thelower part has four side walls, wherein the pair of first straight barsand the mask are taken within the four side walls of the frame and fixedinto the frame and mask supporting member by the four side walls and theconnecting members coupled with the first and second connecting holes,wherein the pair of first straight bars are separated and parallel witheach other, wherein the mask supporting member has a pair of secondstraight bars that are separated and parallel with each other tocorrespond to the pair of first straight bars, respectively, wherein thepair of first straight bars and the pair of second straight bars fix afirst side portion and second side portion of the mask, parallel withthe first side portion, in the mask, wherein the first and second sidewalls of the frame have a long-edge, directly connecting first andsecond side surfaces of the mask, wherein a long-edge of the frame isparallel to a long-edge of the mask, and wherein the third and fourthside walls of the frame have a short-edge, separated from third andfourth side-surfaces of the mask, wherein a short-edge of the frame isparallel to a short-edge of the mask.
 2. The method of claim 1, whereinthe mask includes a mask pattern.
 3. The method of claim 1, wherein themask supporting member is formed of a UV transparent material includingone of acryl and quartz.
 4. The method of claim 1, wherein the UVtransparent mask supporting member further includes a pair of thirdstraight bars, the pair of third straight bars connected with the pairthe second straight bars and supporting third and forth side portions ofthe mask.
 5. The method of claim 1, wherein the mask holder furthercomprise a secondary mask supporting member, the secondary masksupporting member being in the frame.
 6. The method of claim 1, whereinthe upper part is formed of a UV transparent material including one ofacryl and quartz.